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-   -   I finally got to experience the great Death Wobble!! (http://www.wranglerforum.com/f210/i-finally-got-to-experience-the-great-death-wobble-11620.html)

jherrin215 09-19-2007 05:54 PM

I finally got to experience the great Death Wobble!!
 
I have had my new lift on for about 2 weeks now and have had some popping in the front end so today I decided to figure out what it was. I have 1 3/4 spacers and 2 inch teraflex springs. I have a 1 in BL and 1 in MML and I dropped the TCase maybe 1/4 inch. I ordered a new rear track bar relocation bracket and am going to get an adjustable front trackbar, but anyway back to the story. The popping sounded like it was coming from the swaybar links because they are too short with the new lift. I decided to unhook them today and drive it down the road and see how bad it was because I usually only drive about 5-6 miles a day. I didn't have any popping. As I was coming back to the house I hit a reflector in the middle of the road and that joker went wild. I about crapped my pants when it first started happening then I figured out what it was. I have tried to make it happen ever since I put on my lift and it never once acted like it would until I had that sway bar disconnected. Needless to say I came back home and reattached the sway bar and I am just going to stop messing with it until I get some of the components I need and install them.

AzTJ 09-19-2007 05:59 PM

Fun isn't it? :D

4Jeepn 09-19-2007 06:03 PM

sounds more like that's bumpster.. as when you hit an object and it bumps steering of the jeep... Death wobble happens on its own....

jherrin215 09-19-2007 06:11 PM

Well it could have just happened while I hit the reflector. I didn't think the reflector was big enough to cause anything like that. Yeah AZ it was real fun. It felt like riding a bull on cocaine!!

AzTJ 09-19-2007 06:26 PM

Quote:

Originally Posted by 4Jeepn (Post 138595)
sounds more like that's bumpster.. as when you hit an object and it bumps steering of the jeep... Death wobble happens on its own....

not all ways. DW can be set off by a bumper in the road. I've had it happen in our MJ

matt01tj 09-19-2007 08:13 PM

"I have tried to make it happen ever since I put on my lift" why would you try to make it happen

mrbigjeep 09-19-2007 08:27 PM

to see if it would do it so you can find out if you have any problems on the front end

upinar 09-19-2007 08:37 PM

It was defineltly the death wobble if it violently shook. Death wobble could start on a bump and usually does. When i was battling the death wobble months ago, every bump set it off. Bump steer usually starts it.

jherrin215 09-19-2007 10:40 PM

That is the only time it has ever happened. I have hit millions of bumps even some pretty good ones on bridges and things but have never had any kind of shaking until today. It was real bad, felt like the tires were gonna come off the rims!! I think the reason it really cut loose was because the sway bar was disconnected. We will leave it hooked up from now on at least until I get my new track bar parts installed and some different control arms!!

nregas1 09-19-2007 10:51 PM

Everytime I enjoyed that experience it was set off by a bump. Not all bumps, just special bumps. The right size at the right speed that will get those tires pulling against each other in harmony. I never had bump steer though. You should recognize bump steer just as easily as DW. You'll dart off to the L or R just b/c of a bump.

jherrin215 09-20-2007 05:20 AM

I am 99% sure it was DW! I couldn't think of any better words to describe what was going on than that. Whoever gave it that name hit the nail smack on the head!!

kg4kpg 09-20-2007 07:08 AM

Quote:

Originally Posted by AzTJ (Post 138606)
not all ways. DW can be set off by a bumper in the road. I've had it happen in our MJ

Oh yea, a bump got me this morning heading for the interstate. I haven't adjusted my toe-in yet from the lift, have to wait until Saturday cuz I work so late. I like my morning tea shaken, not stired. :D

04blackunlimited 09-20-2007 07:17 AM

Hopefully you can get it figured out quicker than I am. I have had my jeep in the shop 2 times for alignment adjustments. Still have the shake.

kg4kpg 09-20-2007 07:22 AM

I learned quickly with my last jeep about DW. I just corrected the toe-in with my trusty tape measure and wrenches and it never happened again. Well, I did add a stabilizer, but I don't know if it made any difference. I just wanted it to match the shocks. :)

04blackunlimited 09-20-2007 07:32 AM

yeah thats the same thing that I did with the steering stabilizer. on my toe settings they have both side set to .20 the max is .21 RE said that was good.. Is this right?

kg4kpg 09-20-2007 08:08 AM

Don't quote mew because my way may not be the proper way, But I set the front tires where there is only an 1/8th of an inch difference from the front side to the back side. It usually takes me a couple tries driving around the block and re-measuring but it hasn't failed me yet. Then I adjust the steering wheel. I'll do this jeep this weekend and I'll do it again after I add an adjustable track bar.

04blackunlimited 09-20-2007 08:23 AM

Well I'm gonna take it to another shop on monday, if they cant figure it out I think I'll trade it in lol

AzTJ 09-20-2007 02:29 PM

It may have something to do with those ridiculous Thornbird tires.

jherrin215 09-20-2007 02:34 PM

Yeah I have heard numerous times that unbalanced tires are the #1 cause of DW. Having thornbirds I would assume that there is a good chance they aren't balanced perfectly. That could be a great amount of your problem!!

ygohome 09-20-2007 02:40 PM

Quote:

Originally Posted by jherrin215 (Post 138586)
... I have 1 3/4 spacers and 2 inch teraflex springs... As I was coming back to the house I hit a reflector in the middle of the road and that joker went wild. I about crapped my pants when it first started happening then I figured out what it was...

I bet that crazy steering is from your caster angle or lack of it. you have over 3.5" of lift over stock with stock length front arms, is that right? If so then your caster angle is not set to what it should be. By adding the taller coils and spacers the C or inner knuckles are straight up and down... like this "|"... when they should be at an angle like this "/"... replacing the front lower arms with slightly longer aftermarket arms or adjustable arms or cam bolts will correct that angle.

With the knuckles straight verticle, any little bump in the road causes the steering to go crazy.

jherrin215 09-20-2007 04:01 PM

That is the only time it has ever done anything. I have had it like that for about a month now and never had any hint of any type of wobble. I drove it that day with the sway bar disconnected for about 5 miles and it went nuts on me. I have driven it about 30 miles since I reconnected the sway bar and nothing again. Also I thought that when you replaced the lower CA's they were shorter and the uppers were a tad bit longer to help twist the axle housing more upright to line the drive shaft up better??

ygohome 09-20-2007 06:35 PM

if your jeep isn't having anymore problems then I wouldn't change anything. But regarding your question...the front axle is a little different than the rear... in the rear, caster is not involved so the upper arms can be lengthened/adjusted to point the pinion directly at the tcase, if you have a cv driveshaft.

And in the front, your correct, the pinion/driveshaft angle does take presidence over the caster angle... but we have to lengthen the front lower arms at least a little to get some of the caster angle back. Its a fine line to balance between pinion angle and caster angle which is why I leave it to my jeep mechanic/alignment specialist and I don't mess with those measurements myself (which makes me a total web wheeler). :)

But on my jeep I have 3.5" coils which is about the same height your sitting at. All of my arms were stock and I had pretty bad bump steeer/death wobble or whatever its called. I also had removed my front sway bar completely previously so maybe thats why you only experience deathwobble with the sway bar removed. To fix my problem though I didn't want to add the swaybar back on... so my mechanic installed adjustable front lower arms and lengthened them just a little longer than the stock lower arms. THe death wobble and bump steer were completely gone even without the front swaybar. There was a limit on how much he could lengthen the front lowers though because he didn't want to negatively affect the front pinion angle... again, pinion angle takes presidence over caster.

jherrin215 09-20-2007 06:55 PM

Thanks for your reply. That makes sense 100%. I have thought about getting some stock arms and lengthening then and bracing them internally then installing the modified arms instead of buying new ones. The only problem is figuring out how much to lengthen them. But if i did do too much I could always trash them and put my stock ones back on!!

ygohome 09-20-2007 07:06 PM

be carefull with that though... would be terrible if the welds should break or if they rip apart or would just plain drive horrible if the length wasn't adjusted properly. Cam bolts aren't expensive (under $10 or $15) if you want to keep your stock arms.

jduran 09-20-2007 11:13 PM

did u fix the problem ?? i think i have the dw it only happens at 50mph

nregas1 09-20-2007 11:49 PM

You won't "think" you have DW when it happens.

jherrin215 09-21-2007 12:58 AM

I agree with that!! If you have death wobble the first time you should immediately feel a warm lump in the seat of your pants!! That's the sure fire way to know if it is DW. I think mine just showed up because of the sway bar being disconnected. I haven't had it happen again since I reconnected it.

04blackunlimited 09-21-2007 05:23 AM

Quote:

Originally Posted by AzTJ (Post 138949)
It may have something to do with those ridiculous Thornbird tires.



Funny thing is that when I had the thornies on it I didnt get the death wobble. Then I switched the tires back to my stockers and I have it. lol

nregas1 09-21-2007 10:54 AM

Quote:

Originally Posted by 04blackunlimited (Post 139279)
Funny thing is that when I had the thornies on it I didnt get the death wobble. Then I switched the tires back to my stockers and I have it. lol

Had similar experience. Had terrible DW with my 31 BFG AT's. Switched back to my worn out 33 MT's and DW is about 95% gone.

04blackunlimited 09-21-2007 11:13 AM

Quote:

Originally Posted by nregas1 (Post 139382)
Had similar experience. Had terrible DW with my 31 BFG AT's. Switched back to my worn out 33 MT's and DW is about 95% gone.



Anyone want a set of stock tires and rims with a good set of goodyears gsa's? lol :punk:


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